Intro: At previous VSS meetings, we reported that: When 6-month-old infants were presented with the concave face illusion display, lit from below, they reach more often to the apparently closest center of mask when viewing it monocularly and to the actually closer edges of the mask when viewing it binocularly. This indicates that they perceive the concave mask as convex in the monocular viewing condition. In a second study the mask was inverted and lit from the side to reduce its face-like appearance. Infants reached more often to the center of mask in the monocular condition to the same degree as in the first study. This suggests that reducing the face-like appearance of the display may not influence the infant’s perception of the mask as strongly as it does with adults, who perceive a stronger illusion when the face is presented upright than when it is inverted (Papathomas & Bono, 2004). The current study aimed to investigate whether infants’ use of a general convexity assumption by presenting the infants with a concave object that is unfamiliar to the infant. Method: Using a within-subjects design, we presented 6-month-old infants (n=22) with an unfamiliar concave object and observed the trajectory of their reaches in the binocular and monocular viewing conditions. Results: Infants reached more often to the center of the concave object in the monocular condition (61%) than in the binocular condition (32%). A paired sample t-test revealed a significant difference between the means (t=-3.05, P <.01), with a large effect size, Cohen’s d= .9159. Discussion: These results suggest that the infants employ a general convexity assumption and perceive the concave object as convex when binocular information for depth is not available. When binocular cues specify the actual 3-D layout of the display they perceive it as convex.